Author(s): Victor F. Petrenko
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Keywords: No Keywords
Abstract: A new experimental technique is proposed for determination of such crack parameter as velocity, width and elastic strain. The technique is based on measurement of electrical signals generated by growing and stable cracks in ice. Theoretical concepts and experimental configurations of the technique are described. Some examples of crack velocity determination and preliminary results for artificially initiated and occasionally appearing cracks are given. The velocities of the cracks are found in a wide range, from 50 m/s to 1170 m/s. The maximum observed velocity is in good agreement with data on high speed photography obtained by Sato and Wakahama, 1991. A width of about tens of micrometers is found for small intergrain cracks. Measurements of elastic strain distribution in the vicinity of a crack tip give results that are close to the prediction of the theory of elasticity, while there is a noticeable discrepancy at a distance comparable with a crack length. Though the technique looks quite promising, more efforts are necessary to obtain systematic results on crack velocity dependence on stress, temperature and ice structure.
Year: 1992